#include "SceTypes.hpp"
#include "prx/libc/include/Api.hpp"
#include "prx/libkernel/include/Api.hpp"
#include <atomic>
#include <chrono>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <filesystem>
#include <fstream>
#include <source_location>
#include <stdexcept>
#include <string>
#include <thread>

namespace {

constexpr int Efault = 14;
constexpr int Ebusy = 16;
constexpr int Einval = 22;
constexpr int Enospc = 28;
constexpr int Eagain = 35;
constexpr int Etimedout = 60;
constexpr int Eoverflow = 84;

void Require(bool condition, std::source_location location = std::source_location::current()) {
    if (condition) return;
    std::fprintf(stderr, "check failed at line %u\n", static_cast<unsigned>(location.line()));
    std::exit(1);
}

int Error() {
    return *__error_nid_postfix();
}

KernelTimespec FromNow(std::chrono::milliseconds delay) {
    const auto when = std::chrono::system_clock::now() + delay;
    const auto nanoseconds = std::chrono::duration_cast<std::chrono::nanoseconds>(when.time_since_epoch()).count();
    return {nanoseconds / 1000000000, nanoseconds % 1000000000};
}

int Value(std::intptr_t id) {
    int value = -1;
    Require(ksem_getvalue_nid_postfix(id, &value) == 0);
    return value;
}

void Counting() {
    std::intptr_t id = -1;
    Require(ksem_init_nid_postfix(&id, 0x80000000u) == -1 && Error() == Einval);
    Require(ksem_init_nid_postfix(nullptr, 1) == -1 && Error() == Efault);
    Require(ksem_init_nid_postfix(&id, 2) == 0 && id >= 0);
    Require(Value(id) == 2);
    Require(ksem_trywait_nid_postfix(id) == 0 && ksem_wait_nid_postfix(id) == 0 && Value(id) == 0);
    Require(ksem_trywait_nid_postfix(id) == -1 && Error() == Eagain);
    Require(ksem_post_nid_postfix(id) == 0 && Value(id) == 1);
    Require(ksem_getvalue_nid_postfix(id, nullptr) == -1 && Error() == Efault);
    Require(ksem_destroy_nid_postfix(id) == 0);
    Require(ksem_post_nid_postfix(id) == -1 && Error() == Einval);
    Require(ksem_init_nid_postfix(&id, 0x7fffffffu) == 0);
    Require(ksem_post_nid_postfix(id) == -1 && Error() == Eoverflow);
    Require(ksem_destroy_nid_postfix(id) == 0);
}

void Timed() {
    std::intptr_t id = -1;
    Require(ksem_init_nid_postfix(&id, 0) == 0);
    const KernelTimespec invalid{0, 1000000000};
    Require(ksem_timedwait_nid_postfix(id, &invalid) == -1 && Error() == Einval);
    const auto deadline = FromNow(std::chrono::milliseconds(150));
    const auto start = std::chrono::steady_clock::now();
    Require(ksem_timedwait_nid_postfix(id, &deadline) == -1 && Error() == Etimedout);
    Require(std::chrono::steady_clock::now() - start >= std::chrono::milliseconds(100));
    Require(ksem_post_nid_postfix(id) == 0);
    const auto later = FromNow(std::chrono::seconds(5));
    Require(ksem_timedwait_nid_postfix(id, &later) == 0 && Value(id) == 0);
    Require(ksem_destroy_nid_postfix(id) == 0);
}

void Blocking() {
    std::intptr_t id = -1;
    Require(ksem_init_nid_postfix(&id, 0) == 0);
    std::atomic<int> result{-2};
    std::thread waiter([&] { result = ksem_wait_nid_postfix(id); });
    std::this_thread::sleep_for(std::chrono::milliseconds(150));
    Require(result == -2);
    Require(ksem_destroy_nid_postfix(id) == -1 && Error() == Ebusy);
    Require(ksem_post_nid_postfix(id) == 0);
    waiter.join();
    Require(result == 0 && Value(id) == 0);
    Require(ksem_destroy_nid_postfix(id) == 0);
}

void Identifiers() {
    Require(ksem_post_nid_postfix(-1) == -1 && Error() == Einval);
    const auto path = "anyps5-ksem-stale-" + std::to_string(std::chrono::steady_clock::now().time_since_epoch().count()) + ".bin";
    { std::ofstream stream(path); stream << "x"; }
    const int plain = open_nid_postfix(path.c_str(), 0, 0);
    Require(plain >= 0);
    Require(ksem_post_nid_postfix(plain) == -1 && Error() == Einval);
    Require(close_nid_postfix(plain) == 0);
    std::intptr_t id = -1;
    Require(ksem_init_nid_postfix(&id, 1) == 0);
    Require(close_nid_postfix(static_cast<int>(id)) == 0);
    Require(ksem_post_nid_postfix(id) == -1 && Error() == Einval);
    const int reused = open_nid_postfix(path.c_str(), 0, 0);
    Require(reused >= 0);
    Require(ksem_post_nid_postfix(reused) == -1 && Error() == Einval);
    Require(ksem_getvalue_nid_postfix(reused, nullptr) == -1 && Error() == Einval);
    Require(close_nid_postfix(reused) == 0);
    Require(ksem_init_nid_postfix(&id, 1) == 0);
    const int other = open_nid_postfix(path.c_str(), 0, 0);
    Require(other >= 0 && other != id);
    Require(dup2_nid_postfix(other, static_cast<int>(id)) == static_cast<int>(id));
    Require(ksem_post_nid_postfix(id) == -1 && Error() == Einval);
    Require(ksem_trywait_nid_postfix(id) == -1 && Error() == Einval);
    Require(close_nid_postfix(static_cast<int>(id)) == 0 && close_nid_postfix(other) == 0);
    std::filesystem::remove(path);
}

bool Throws(void (*call)(int), int argument) {
    try {
        call(argument);
    } catch (const std::runtime_error&) {
        return true;
    }
    return false;
}

void Duplicates() {
    std::intptr_t id = -1;
    std::intptr_t target = -1;
    Require(ksem_init_nid_postfix(&id, 1) == 0 && ksem_init_nid_postfix(&target, 1) == 0);
    Require(Throws([](int descriptor) { dup_nid_postfix(descriptor); }, static_cast<int>(id)));
    static int destination = -1;
    destination = static_cast<int>(target);
    Require(Throws([](int descriptor) { dup2_nid_postfix(descriptor, destination); }, static_cast<int>(id)));
    Require(dup2_nid_postfix(static_cast<int>(id), static_cast<int>(id)) == static_cast<int>(id));
    Require(Value(id) == 1 && Value(target) == 1);
    Require(ksem_destroy_nid_postfix(id) == 0 && ksem_destroy_nid_postfix(target) == 0);
}

void Limit() {
    std::intptr_t ids[30] = {};
    for (auto& id : ids) Require(ksem_init_nid_postfix(&id, 0) == 0);
    std::intptr_t extra = -1;
    Require(ksem_init_nid_postfix(&extra, 0) == -1 && Error() == Enospc && extra >= 0);
    Require(ksem_post_nid_postfix(extra) == -1 && Error() == Einval);
    Require(ksem_destroy_nid_postfix(ids[0]) == 0);
    Require(ksem_init_nid_postfix(&ids[0], 0) == 0);
    for (const auto id : ids) Require(ksem_destroy_nid_postfix(id) == 0);
}

}

int main() {
    Counting();
    Timed();
    Blocking();
    Identifiers();
    Duplicates();
    Limit();
    std::puts("ksem unnamed semaphores passed");
    return 0;
}